Around 100 onlookers watched as Cairns Turtle Rehabilitation Centre [CTRC] volunteers released the juvenile turtle at Trinity Beach on Sunday.

Believed to be around 10-years-old, the turtle was first taken in late last year after being spotted in Trinity Inlet with the deadly fibropapilloma virus, a condition which causes tumors to grow on their body.

Volunteer Christian Miller said the release was a rare opportunity for bystanders to witness a turtle release.

"It's a bit unusual. Most of the releases we do are from an island or the outer reef," he said.

"A lot of people were following the turtle into the water. The great thing was that it was from a beach and people could just come and attend without a boat.

"All the people just swarmed around our volunteers and asked a million questions. They wanted to get involved and see what's happening in Cairns with our turtles. It was really beautiful."

CTRC are also setting up a new 30-tank turtle centre on Fitzroy Island which Mr Miller said was progressing well.

"We're just getting the first public tank ready and a turtle is coming out in about an hour. The building is painted, we're doing up signs, the logos. Everything is happening," he said.

Mr Miller said he expects to open the facility in the next two weeks which will accommodate turtles who can't be cared for at CTRC's current centre in Portsmith which has 14 tanks.